Collaborative Research: Three-dimensional Analysis of Dental Microwear in Primates

University Of Arkansas, Fayetteville AR

Investigators

Abstract

This project will develop a new, improved way to reconstruct the diets of past humans and fossil animals using microscopic use-wear on their teeth. Recent studies of living primates have shown associations between diet and patterns of dental microwear. Microscopic use-wear has been found on the teeth of past peoples and a broad range of extinct animals. Conventional approaches to analyzing this wear have involved imaging tooth wear surfaces by scanning electron microscopy (SEM), followed by counting and measuring individual wear features on resulting photomicrographs. This approach has not been ideal, because the SEM does not provide a true representation of tooth surfaces in three dimensions, and because identification and measurement of individual features is time-consuming, subjective and subject to high interobserver error. The recent developments of white light confocal microscopy and scale sensitive fractal analyses obviate these problems, promising a more objective, repeatable, 3D characterization of dental microwear. The instrument provides 3D coordinates representing surfaces at a resolution equivalent to that used by most SEM microwear studies. Fractal analyses provide objective, repeatable quantitative characterization of surfaces. A recent Major Research Instrumentation grant (NSF BCS-0215830) has allowed us to purchase a white light confocal microscope with scale sensitive fractal analysis software. This proposal requests funds to adapt this technology for dental microwear analysis, and to establish a baseline series of 3D microwear patterns for living primates with known diets. This baseline will allow us to infer diets of past peoples and extinct animals using microwear patterns on fossil teeth. This new approach will eliminate major sources of error, and increase power to resolve differences between species. Moreover, rapid surface characterization will allow examination of large samples to assess variation within species and to make finer distinctions between species. Further, because results are repeatable, it will allow direct comparisons of data between researchers, promising a better understanding of the lives of our distant ancestors, and other fossil species. Just as the SEM and quantification advanced microwear studies 25 years ago, so too will confocal microscopy and metrological analyses today. As with other scientific endeavors, the history of dental microwear studies shows a feedback loop between research and technological innovation. This repeatable, automated procedure will allow researchers to share data and stimulate new uses of this technology. Our data for the extant baseline series will be available on-line for all those interested. This project will be coordinated from the University of Arkansas, and will involve training and collaboration between students in Arkansas, Massachusetts, Maryland and Pennsylvania. This project will support cutting edge research in the state of Arkansas and bring a scientific research experience to students who are often first generation college attendees. It will include technology training that will prepare students from this geographically underrepresented group for technology sector jobs.